 "Photo: Maddie Crum/The Daily Texan")
Zombies, the longtime subjects of savage horror movies, have now become the subjects of epidemiological studies.
A mathematical analysis of a hypothetical zombie plague by two researchers from Canadian universities inspired UT ecology, evolution and behavior graduate student Sam Scarpino to create models of his own.
“There are so many different aspects of the real world that may or may not be incorporated in epidemiologic simulations, so no one model will be perfectly accurate, but I think mine was close, given my assumptions,” Scarpino said.
All diseases have modes of transmission, Scarpino said. The three main modes are susceptible people who contract the disease, infected people who transmit the disease and people who are no longer sick — whether deceased or cured.
“Scientifically speaking, a very severe infection that jumped from another species might cause a zombie epidemic,” Scarpino joked.
But, Scarpino said, zombie-like behavior is not as far-fetched as it may seem.
“It’s common knowledge that zombies seek out non-zombies to infect,” Scarpino said.
“Mosquitoes infected with malaria act the same way. They actually increase the number of times they feed on hosts, which increases the transmission of the disease. Humans infected with malaria are actually more attractive to mosquitoes than uninfected humans,” he said.
Scarpino simulated what would happen to Travis, Bexar, Comal and Hays counties in 50 days if a single zombie, originating in Travis County, were to begin infecting others.
According to Scarpino’s models, the bigger populations of Travis and Bexar counties would be wiped out faster than the populations of Comal and Hays counties.
After five days of infection, only a small percentage of people would be affected in any of the counties, but after 35 days, more than 75 percent of Travis County would be infected, Scarpino said.
In his model, Scarpino assumed that there would be a “homogenous mixing of people in a county” where everyone interacts with everyone else. He also assumed that people would move freely about a county and few infected people would move to other counties and spread the disease.
Scarpino explained that if there was a zombie epidemic, the worst reaction would be to aggregate all non-zombies in a safe haven such as a military base — a tactic commonly seen in popular zombie movies with predictable results.
“People who are latently infected with any disease would simply wipe out the entire population of non-infected people,” Scarpino said. “This happens in every movie and always has disastrous results.”
